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1. 7 2 1 Basic run time configuration 7 2 2 Overall MPT system parameters eoe X nes 0 Ge a arts D as a 7 2 3 Camera daemon parameters uen us Neue nn Tent Where re o 7 2 4 Timing and filter parameters 9 eo des LUE BRR AR Sat de 7 2 5 Cosine ambiguity recovery control parameters 7 2 6 Find starburst parameters s x ox ox etage dre r Ju Comments in xml files 2222 eed eee es ie Pos mcr POE Due 4 3 Calibration data ai u dou RE UE E ERES ERE JT Fr Measured laten ies uc a uter nes ee ica ea Pc ig Ra Neg Dt eg RSID ne TAC SOC UIP Cet kllsE cocus dote d org So Bw amp og s eae Se Bate Sod Soy dius 52 52 32 53 53 54 Revised Mar 17 2013 Page iii List of Figures Sn D 10 11 12 13 14 15 16 17 An MPT image with marker 61 o cue Cos TE ANS RATS te he me 1 MPT camera lighting unit aoaaa e gr X ex DX eel Cen x XX 2 Bolt II moir Phase tracking processing computer 2 Cable connections to the CLU 384ib camera lighting unit 4 Back panel of Bolt II computer showing cables 4 Screen shot of the Bolt II computer upon booting Program TrackMPT Marker is automatically launched 2 23 ns Gd 2a he p RUP ER 5 Block diagram showing overview of the real time MPT system showing CameraDaemon and the MPT tasks 10 Block diagram of the real time MPT system sh
2. Revised Mar 17 2013 Page 20 MPT Users Manual Section 4 1 3 Detailed User Manual 4 1 CameraDaemon help message CameraDaemon if executed with the help option responds with the following text user Bolt II bin CameraDaemonFW help Usage CameraDaemon options v Verbose mode messages printed describing operation V Very Verbose mode many messages printed describing operation help This message F 20 Set Frame Rate to 20 fps R 2 Set Image Save Rate to 2 ips S 100 Set Image Save Count to 100 images U 5 Set UnderSample Rate to every 5th image E 1000 Set Exposure to 1000 micro seconds D tmp Load Images from Directory T 24 Launch an RGR instance for marker 24 p Turn On Preview Window C Stream cropped images to disk files cropped images centered on pHintXY received from TrackMPT Marker g Continuous graphing of logging data G Report statistics when graphing updates r Disable automatic saving of 6 images when tracking stops Demo mode switches d Continuously Loop from Directory demo mode only n Suppress looking for frame number in image file name demo mode only W Wait to load images until RGRs s are ready demo mode only Preview window active keystrokes Show maximum intensity Preview binary image painting pixels at maximum level white Terminate preview binary image Save next nImagesToSave images to disk Save the ring buffer to
3. 5 where k is the sample index Controlling filtering of individual parameters Vector of logical values bRunFilter controls whether an individual value in is filtered lt bRunFilter gt true true true true true true lt bRunFilter gt Set values to false to suppress filtering The elements of P are T os 6 X Z 7 See section 7 1 for definitions of the rotations Filter Parameters The filter parameters are set by setting Bfilter and Afilter in ConfigRunTime xml Example values are No filtering se This is a 5th order non filter With these parameters data are passed through without change equivalent to turning off filtering lt Bfilter gt 100000 lt Bfilter gt lt Afilter gt 1 0 0 0 0 0 lt Afilter gt gt Light filtering lt This is a 5th order Butterworth wn 1 3 10 Hz with 60 Hz sampling group delay 5 5 samples lt Bfilter gt 0 0106119 0 0530595 0 1061191 0 1061191 0 0530595 0 0106119 lt Bfilter gt lt Afilter gt 1 0000000 1 6448489 1 5866151 0 8048818 0 2299491 0 0272522 lt Afilter gt Revised Mar 17 2013 Page 30 MPT Users Manual Section 4 2 2 Detailed User Manual Heavy filtering lt This is a 5th order Butterworth wn 1 48 0 625 Hz with 60 Hz sampling group delay lt Bfilter gt 1e 6 0 0338194 0 1690972 0 3381945 0 3381945 0 1690972 0 0338194 lt B lt Afilter gt 1 0 4 7882108 9 1750976 8
4. Revised Mar 17 2013 Page 61 MPT Users Manual Section 7 2 5 Appendices 7 2 4 Timing and filter parameters Field Name Example Significance Allowed Values Data irqDelay_uS 8 Delay between rising edge of 0 999 999 the external timing signal to Tirq registered frameDelay uS 0 Delay from end of exposure 0 999 999 to time tagging of image bEnablePCA_Element true 6 Vector controlling whether 6 vector of true false false a given element of vector S Values must be logical is included in PCA Boolean type Estimation jFilterInitializationMode 2 Controls when the filter state 0 1 2 is initialized see section 4 2 2 1 bRunFilter true Controls which elements in true false true P are filtered using Bfilter and Afilter see section 4 2 2 1 Bfilter 1 0 B polynomial of Butterworth Given by filter design filter on Z Afilter 1 0 A polynomial of Butterworth Given by filter design filter on Z Table 5 Significance of ConfigRunTime xml entries continued 7 2 5 Cosine ambiguity recovery control parameters Parameters controlling Cosine Ambiguity Recovery see section 3 1 6 These parameters are generally not user adjustable Revised Mar 17 2013 Page 62 MPT Users Manual Section 7 2 7 Appendices Field Name Example Significance Allowed Values Data bEnableCosineAmbiguityRecovery
5. Figure 2 MPT camera lighting unit Figure 3 Bolt II moir Phase tracking processing computer 1 1 Overview of this manual The quick start guide follows in section 2 followed by an introduction to the theory of operation of the MPT system in section 3 detailed user manual in section 4 MPT system adjustments in section 5 and trouble shooting guide in section 6 The appendices section 7 detail notation and MPT configuration files Revised Mar 17 2013 Page 2 MPT Users Manual Section 2 1 1 Quick Start Guide 2 Quick Start Guide 2 4 Starting the MPT hardware 2 1 1 Cabling Make the data connection between the MPT camera lighting unit and the MPT computer In the MT 384ib this is done with fiber optic The fibre and power connections to the CLU 384ib are seen in figure 4 1 Remove and save the fiber optic plug from the CLU fiber optic connector Use this plug to prevent ingress of foreign matter when ever the CLU is not connected to fiber 2 Connect the fiber optic cable 3 Connect the coax power cable Note for high field applications both the fiber optic cable and coax have one low susceptibility termination Connect the fiber optic cable to the Bolt II computer as seen in figure 5 Remove and save the fiber optic plug from the Bolt II fiber optic connector Use this plug to prevent ingress of foreign matter when ever the Bolt II is not connected to fiber Make power network monitor
6. Manual Section 4 6 2 Detailed User Manual The log dat file can be loaded into Matlab and analyzed directly or with a plotting or a planarity analysis program gt gt load DRTLog M023 2010 02 06 23 57 48A 10g dat PlotDRTResults gt gt EvaluatePlanarity 4 6 1 Fields of the A logging file The DRTLog A log file contains the information transmitted in a UDP packet The fields are Engineering Data Logging message time UNIX time when program TrackMPT Marker called logging UDP Packet Version Status Frame Number Marker ID Number Pose Data not through estimator X Y Filtered Z in milli meters this is the only place in the field reflecting the filtered Z data Quaternion qr dx dy 4z Timing Information Frame Time Count of interrupt events Interrupt time An example line from an A logging file is LT 15 16 05 270 V 03 S 00000 M 022 F 00000052 XYZ 0049 332 0079 464 2344 014 Q 0 07197 0 22911 0 94558 0 21956 FT 0000000001 232 18 00 IT 0000000000 000 tSScknot 014 7708 024 7561 2346 313 001 9408 030 1967 001 2054 This was broken into multiple lines for readability from a single log file line Revised Mar 17 2013 Page 43 MPT Users Manual Section 4 6 2 Detailed User Manual 4 6 2 Fields of the B logging file The DRTLog B log file contains engineering data The fields are Logging message time UNIX time when progr
7. bEnableCosineAmbiguityRecovery to true or false in file ConfigRuntime xml see section 7 2 Cosine ambiguity recovery is rarely required 3 1 7 Accelerated Starburst detection For detection the starburst landmark of an MPT marker must have an intensity above a threshold level To accelerate detection of the starburst landmark a minimum intensity threshold is set and regions below this threshold are not searched The threshold is set by parameter StarburstPreSearchIntensityThreshold in file ConfigRunTime xml see section 7 2 3 1 8 Automatic detection of Physical Marker ID Number The MPT system can automatically detect and track a recognized marker as described in this section First manual declaration of the Marker ID Number is described then automatic detection Manual declaration of the Marker ID Number bEnableAutoMarkerDetect false When ConfigRunTime xml parameter bEnableAutoMarkerDetect is set to false program TrackMPT Maker will look in each image for the Marker ID Number given in ConfigRunTime xml or on the com mand line If a different marker is presented it will not be recognized Automatic detection of the Marker ID Number bEnableAutoMarkerDetect true When ConfigRunTime xml parameter bEnableAutoMarkerDetect is set to true with some restrictions program TrackMPT Maker will identify a new marker presented to the camera and automatically begin to track that marker Automatic
8. Mar 17 2013 Page 48 MPT Users Manual Section 4 9 1 Detailed User Manual nGrabs 13420 amp PCA EstimatorLength 7fdcba326000 7fdcbab5a088 PCA EstimatorLength 400 Image Ring Frame Ring 0 FrameNumber 00023270 tv sec 00241858 tv nsec 199458779 Frame Ring 1 FrameNumber 00023272 tv sec 00241858 tv nsec 260452223 Frame Ring 2 FrameNumber 00023274 tv sec 00241858 tv nsec 321441865 Frame Ring 3 FrameNumber 00023262 tv sec 00241857 tv nsec 955495552 Frame Ring 4 FrameNumber 00023264 tv sec 00241858 tv nsec 016484187 Frame Ring 5 FrameNumber 00023266 tv sec 00241858 tv nsec 077475693 Frame Ring 6 FrameNumber 00023268 tv sec 00241858 tv nsec 138468205 pSharedMemory gt MarkerLookup 23 0 MarkerData 0 MarkerIDNumber 23 bGrabbed 0 TRUE bGrabbed 1 TRUE bGrabbed 2 TRUE bGrabbed 3 TRUE bGrabbed 4 TRUE bGrabbed 5 TRUE bGrabbed 6 TRUE MarkerData 23 MarkerData 23 MarkerData 23 MarkerData 23 EstimatorData OuterProdComposite PoseComposite 39832 97 36677 59 1574 62 26940 00 224464 93 42244 80 3991 63 36677 59 33772 18 1449 88 24805 94 206683 92 38898 38 3675 44 1574 62 1449 88 62 24 1064 95 8873 23 1669 96 LST E9 26940 00 24805 94 1064 95 18220 17 151811 07 28571 18 2699 64 224464 93 206683 92 8873 23 151811 07 1264894 67 238056 03 22493 50 42244 80 38898 38 1669 96 28571 18 238056 03 44
9. 1 sx cp Lo Li 2 1 0 0074 pixels mm 70 2800 mm mm x20 mm 67 6 pixels 3 so in this configuration the marker could be tracked to tilt angles slightly over 60 At lower image resolutions the marker may still be tracked but not up to 60 of tilt The maximum tilt is given according to hen 65 cos 60 E aera 9 For example with the above data a 12mm marker can be tracked up to a tilt angle of ERUNT 65 cos 60 A 5 Tees QUE a 0 0074 70 2800 z xd 3 5 Measurement coordinate frames MPT measures the pose of the marker in the camera coordinate frame The imager camera and marker coordinate frames are illustrated in figure 10 Camera frame The position of the camera coordinate frame is defined by the lens of the camera The Z axis of the camera frame Z lies along the optical axis of the lens and the origin of the camera coordinate frame is centered at the lens object side principal point Because it is defined by the optical properties of the lens and will often be within the lens it is not generally possible to mechanically locate the principal point Marker frame The marker coordinate frame is attached to the front face of the maker as seen in figure 11 with the origin of the marker coordinate frame centered on the starburst landmark The Y axis is aligned with the key spoke of the starburst landmark the X axis lies in the plane of the marker and the Z axis is directed outward f
10. 178 267144 Status XYZPRY pales 5 05 5 f 514 178 Example Streamed Data FT 00017 549 S 00000 M 220 F 02343343 XYZPRY 40030 604 0007 631 0189 723 004 7866 088 6715 173 153 FT 00017 560 S 00000 M 220 F 02343344 XYZPRY 40030 605 0007 632 0189 737 004 7827 088 6702 Figure 15 Screen shot showing streaming measurements with example streamed data 81 9 x mm 52 4 44 9 Y mm EVI Is 1 Wi A andy AAA ni U vi NN IV N ui M Vn Jn va y My W Y LV VA MV W y Ww Y A JA A A NE AT j Mi AIN Y Iv APA ev vow y V p v WW Wal AM is A MA ny VM d V y 1782 Figure 16 Graphing output of CameraDaemon TrackMPT Marker Revised Mar 17 2013 Page 33 173 164 MPT Users Manual Section 4 3 2 Detailed User Manual e Followed by the Euler angles pitch roll and yaw Ox 0 and 0 The rotation is given according to vR J R J Ry J Rx J 10 where the elementary rotations are given in Eqn 19 below The Euler angles are calculated in routine RMatrixRxRyRz2Angles m and T j is defined in Eqn 12 below The streaming output can be given in several coordinate frames described in the next section Section 7 1 on coordinate frames is recommended reading before reading the remainder of this section 4 3 1 Available coordinate frames for streaming output For the streaming data the position and Euler angles are given by first calculating
11. 48 03 m Tags DRTLogFile txt F 13675 This is a first tag F 13720 This is a second tag F 13760 This is a third tag 4 9 3 2 Breaking out the log files into segments by the tags If the tags mark regions in the data it may be useful to break out the DRTLog files into segments based on the tags To do this 1 cd into the session directory e g user Bolt II cd Metria Logging Session 2010 10 05 15 48 03 Or user Bolt II GoToMostRecentMPTSession userQBolt II Session 2010 10 05 15 48 03 2 Launch Matlab and add the path back to the Diagnostics directory user Bolt II Matlab gt gt addpath Metria Software MPT_TrackingSystem Diagnostics 3 Run BreakByTags m gt gt BreakByTags TagLineNumbers 24 30 35 132 ALogFileSegmentName DRTLog M023 2010 10 05 15 48 22A 01 10g BLogFileSegmentName DRTLog M023 2010 10 05 15 48 22B 01 10g oO ALogFileSegmentName DRTLog M023 2010 10 05 15 48 22A 02 10g BLogFileSegmentName DRTLog M023 2010 10 05 15 48 22B 04 10g The directory will contain the indicated log files each holding a segment of the record Revised Mar 17 2013 Page 51 MPT Users Manual Section 5 1 1 Trouble Shooting 5 MPT system adjustments 5 1 Adjusting the illumination intensity The illumination intensity should be adjusted such that the peak intensities for pixels on the MPT marker are in the range 150 230 The image
12. 7945960 4 2167989 0 8090885 lt Afilter One set of filter parameters should be uncommented in ConfigRunTime xml see section 7 2 7 The light filtering parameters are shown uncommented above The light and heavy parameters are given by Matlab s Butterworth filter design rule signal processing toolbox required gt gt B A butter 5 10 30 gt gt B A butter 5 1 48 Light filtering 3 dB at 10 Hz for 60 Hz sampling Heavy filtering 3 dB at 0 625 Hz for 60 Hz sampling The B ilter and Afilter parameters can be set to any suitable digital filter design Filter Initialization Mode To suppress startup transients the filter state can be initialized to the state that would be found after a long period of signals steady at the current value This is implement by setting Wout kK 1 Wou k 5 Win kK 1 win k 5 Win k where w k is the current of the corresponding element of P Initialize the filter state according to jFilterInitializationMode in ConfigRunTime xml lt jFilterInitializationMode gt 2 lt jFilterInitializationMode gt Allowed values 0 Do not initialize the filter state 1 Initialize the filter state once on the first measurement of the marker pose in program TrackMPT Marker 2 Initialize the filter on the first measurement of the marker pose in program TrackMPT_Marker and re initialize each time marker tracking is lost and the mar
13. Manual Section 3 1 1 Theory of Operation CameraDaemon Process Disk File py Camera Shared Memory SEE EE ER AO rog Q Camera Daemon t D i 5 Camera Thread cel Ring Buffer i Main Thread of Images Shared MES Memory State i Target Preview Context 00 Thread MPT Logging Server i Thread i Message Queue AS ce ae aia Y Grablmage Queue Y Message Queue i Ready Queue i Display POSIX Inter Process Synchronization Communication Tools TrackMPT Marker Process Message Queue Tr n Viewer Queue Message Queue Logging Queue A Message Queue Logging Queue B Re Lcd 3L TrackMPT Marker 1 a Image o a 3 Emit Results iy UDP Packet Faq ea TrackMPT_Marker 2 5 El mage iter ad 2 d Emit Results UDP Packet LB Y L mo Req TrackMPT_Marker n D LL EE 3 a Image ee EE i Emit Results UDP Packet Y Figure 7 Block diagram showing overview of the real time MPT system showing CameraDaemon and the MPT tasks When the message receive function is called with the appropriate flags the calling
14. detection and tracking occurs when There is only one marker present in the image Only one TrackMPT Marker process is running A calibration file for the presented marker is included in the system installation The Marker Series Number of the marker is either the primary or secondary Marker Series Number see section 4 8 When multiple TrackMPT Marker processes are running either on different markers or for alternate image processing of a given marker automatic detection of the marker ID number should not be used Revised Mar 17 2013 Page 14 MPT Users Manual Section 3 1 9 Theory of Operation 3 1 9 Frame and Interrupt time stamps CameraDaemon provides a mechanism to record the times of external events these times can be used to correlate those external events with image exposure The external event is brought into the Bolt II via a parallel port adaptor which responds to the rising edge of a TTL signal The rising edge TTL signal will cause an interrupt on the Bolt II to register the Interrupt Time Stamp and increment a counter i rgSequenceNum The Interrupt Time Stamp irqTime along with the end of exposure time stamp frameTime and irqSequenceNum are all available via the UDP packet Two timing measurements are provided in the UDP packet generated by MPT system Both measurements are provided in two parts seconds and nanoseconds see section 3 2 1 Frame Time Stamp frameTime This is the time at the
15. disk Read and report camera temperature sensor Flip left to right the preview window Flip top to bottom the preview window Q lt EP orb p aa Q HA fe Quit This will shut down CameraDaemon Revised Mar 17 2013 Page 21 MPT Users Manual Section 4 1 5 Detailed User Manual 4 1 3 4 1 4 4 1 5 Verbosity There may be instances where knowledge of what CameraDaemon is doing may aid in development Two separate levels of verbosity are available to print messages to the terminal window pertaining to CameraDaemon s current operation Moderately verbose user Bolt II bin CameraDaemonFW v Highly verbose user Bolt II bin CameraDaemonFW V By default verbosity is off Frame Rate and Under Sample The frame rate can be set in ConfigRunTime xml or set when running CameraDaemon using the F flag Frame Rate will set the the camera to take FrameRate images per second A camera is limited to a peak frame rate if the FrameRate parameter is set above the limit a message will be displayed and the camera will default to its maximum frame rate user Bolt II bin CameraDaemonFW F 200 The light on the MPT Camera and Lighting Unit will flash at the frame rate set for the camera The Under Sample option allows for synchronous acquisition of images at frequencies below what is acceptable for human subjects while maintaining an acceptable ring flash frequency An under sample rate set to N will pro
16. keyboard video and mouse connections to the Bolt II Power is required Network is required to transmit UDP packets Video is required to preview images such as for aligning the CLU camera Keyboard and mouse are required if optional interaction with MPT images processing or log files is desired Revised Mar 17 2013 Page 3 MPT Users Manual Section 2 1 3 Quick Start Guide Figure 4 Cable connections to the CLU 384ib camera lighting unit Figure 5 Back panel of Bolt II computer showing cables 2 1 2 Logging in to the Bolt II MPT processing computer Energize the Bolt II MPT processing computer Power on depress the circular button on the front of the Bolt II To shut down With video and mouse select user in the upper right corner of the screen select shutdown Without video and mouse depress the power button Revised Mar 17 2013 Page 4 MPT Users Manual Section 2 2 1 Quick Start Guide 2 1 3 Energizing the MPT Camera Lighting Connect the camera lighting unit by coaxial cable to the CLU power supply 2 2 Starting the MPT Software The MPT processing computer runs the Preempt RT real time variant of Fedora Linux When it is booted UNIX Linux commands may be typed at a command prompt and many operations are accessible through the drop down menus accessed along the upper toolbar seen in figure 6 2 2 1 Automatic MPT software startup On boo
17. og 41 RE dr enar deno quede dU Lear c die cp a 59 l entries continued onu ono xs 60 l entries continued zu owe US 61 l entries continued 62 l entries continued Parameters controlling Mle exe ted Sedo oue CP LUE SY 63 entries continued Parameters controlling Fade de qu AS ie adi ae qe i pu we RS i a Sn a nee 63 Revised Mar 17 2013 Page v MPT Users Manual Section 1 0 0 Introduction 1 Introduction v ul s TM n n Moir Phase Tracking or MPT is a single camera 3D motion tracking technology that operates with a passive cooperative marker An MPT motion tracking system comprises 1 One or more moir phase tracking markers figure 1 2 An MPT camera lighting unit or CLU figure 2 3 A Bolt II MPT processing computer figure 3 4 Camera lighting unit power supply The MT 384ib is described in this manual The MT 384ib processes streaming images from the MPT camera lighting unit tracks one or more tracking markers and produces UDP packets with measurement results Additionally log files are produced Some characteristics of MPT are Operation from a single camera eliminating multi camera calibration Automatic tracking of multiple markers Real time tracking Image of 65mm MPT marker Image of 20mm MPT marker at 2 5 meters through mirror Figure 1 An MPT image with marker Revised Mar 17 2013 Page 1 MPT Users Manual Section 1 1 0 Introduction
18. other terms The notation is described here 7 1 1 Positions All metric quantities are marked with the designation of the coordinate system in which they are measured For example P a specifies the position of point a in camera or c coordinates A point a is designated by the subscript and the coordinate frame in which it is expressed is designated by the left superscript e The origin of a coordinate frame is indicated with a knot thus P is the position of the origin of the marker formerly known as target or f coordinates expressed in camera coordinates 7 1 2 Points axes and poses Points are written P Y R3 where P is the position of in camera coordinates and X Y and CZ R are the individual X Y and Z axis elements A pose in Cartesian Camera coordinates is written cp eR 16 Revised Mar 17 2013 Page 55 MPT Users Manual Section 7 1 3 Appendices 7 1 3 and typed cPPtknot where P are the Euler angles Rotations The rotation matrix from marker formerly known as target to camera coordinates at time t t j is specified 1 0 0 1R J 0 1 O Rz j Ry j Rx j 17 0 0 1 R 3 is the Rotation matrix from marker coordinates to camera coordinates where R j Given the location of a point a on the marker P4 we could determine the location of the point in camera coordi
19. process will sleep until a message is available implementing inter process synchronization For example when TrackMPT Marker is running in each of two sessions each will wait for a message on the GrabImage queue If two or more processes are waiting the operating system selects one to receive the message Semaphores The wait and post mechanisms of POSIX semaphores make it possible to assure that only one process at a time enters a critical section of code Only global semaphores appear with the ipcs command described below Handy UNIX commands for managing shared memory message queues and global semaphores ipcs provides information on inter process communication facilities This command lists e Shared memory segments Global semaphores Revised Mar 17 2013 Page 10 MPT Users Manual Section 3 1 3 Theory of Operation Message queues Command ipcs can be used to see currently allocated shared memory segments global semaphores and message queues When MPT is running one shared memory segment and several message queues are visible X Windows also uses several shared memory segments and message queues that are visible with ipcs ipcrm remove shared memory segments semaphores and message queues This can be useful if CameraDaemonFW or TrackMPT Marker dies uncleanly and leaves resources dangling Note launching and exiting CameraDaemon also re initializes the inter process communication resources
20. the g option user 2 Bolt II bin CameraDaemonFW g Notice that graphing doesn t start displaying data until TrackMPT Marker is running See section 4 3 for additional details The MPT Graphing window is illustrated in figures 13 and figure 16 below 100 X fru ME RE 100 1 100 2350 Z mm a T T 2260 60 pitch deg Figure 13 Illustration of the graphing window showing marker pose plotted in Camera Cartesian coordinates When graphing is active statistics of the plotted data can additionally be viewed with the G switch See section 4 4 4 e When Preview and Graphing Window Marking is activated black are drawn at the left and right edges of each axis in the graphing window see section 4 1 7 2 The graphing window can only display data from one marker at a time The marker displayed is the first detected in the current session 4 1 9 Loading images from disk CameraDaemon provides a Demo Mode which does not require a camera In Demo Mode images are loaded from disk instead of being streamed from a camera Demo Mode is activated with the D option followed by the path to a directory containing a set of images Revised Mar 17 2013 Page 26 MPT Users Manual Section 4 2 0 Detailed User Manual user Bolt II bin CameraDaemonFW D tmp Images Additionally there are several options that can only be used with De In no
21. the pose of the virtual marker relative to the physical marker is established Transforms T and T are recorded in the marker context in shared memory see section 3 1 4 and are modified using the UpdateHomogeneousTransforms utility in the bin directory For example user Bolt II MPT TrackingSystem cd bin user Bolt II bin UpdateHomogeneousTransforms 112 2 1 UpdateHomogeneousTransforms Processing Marker Number x LEZ Room Coordinate Mode 2 Acquire from current measurement Virtual Marker Mode 1 Reset to identity matrix Processing completed successfully The current value of transforms 7T and T can be viewed using the ShowSharedMemoryState utility For example with 77 and T set as shown user Bolt II bin ShowSharedMemoryState MarkerData 112 bCaptureRoomCoordinates FALSE MarkerData 112 crT 0 433468 0 898817 0 065064 93 875 0 765005 0 405173 0 500603 48 775 0 476312 0 167221 0 863229 772 927 0 000000 0 000000 0 000000 1 000000 MarkerData 112 rcT 0 433468 0 765005 0 476312 364 776 0 898817 0 405173 0 167221 233 388 0 065064 0 500603 0 863229 648 903 0 000000 0 000000 0 000000 1 000000 Revised Mar 17 2013 Page 35 MPT Users Manual Section 4 3 2 Detailed User Manual MarkerData 112 bCaptureVirtualMarker FALSE MarkerData 112 vtT 1 000000 0 000000 0 000000 0 000 0 000000 1 000000 0 000000 0 000 0 000000 0 000000 1 0
22. 0 UDP Packet emitted Status Figure 14 Basic processing cycle of program TrackMPT Marker MPT Measurement proceeds in these steps Revised Mar 17 2013 Page 28 MPT Users Manual Section 4 2 2 Detailed User Manual 1 Grab the image and predicted marker location with function GrabImage 2 Search for the marker a Search for the marker in the neighborhood of the predicted marker location b If the marker is not identified at the predicted location search the entire image 3 If the marker is identified process the marker 4 If there was a successful measurement run the filter and estimator 5 In all cases generate a UDP packet and logging entry If processing is successful the status is marked st atus 0 in the UDP packet and logging entry 4 2 1 Performance On a Bolt II computer each MPT process is able to process approximately 100 frames per second average throughput MPT processing has variable timing For measurement rates above 80 measurements per second it is recommended to process on two cores Because of the variability in time required to process one image processing on two cores will give the advantages of more reliable processing at the frame rate and reduced temporal jitter in the UDP packet timing MPT runs on the main path of figure 14 in approximate 10 milli seconds If marker tracking is lost and the entire image is searched processing will be delayed for approximately 100 mill
23. 00000 0 000 0 000000 0 000000 0 000000 1 000000 MarkerData 112 tvT 1 000000 0 000000 0 000000 0 000 0 000000 1 000000 0 000000 0 000 0 000000 0 000000 1 000000 0 000 0 000000 0 000000 0 000000 1 000000 the r or room coordinate frame is expressed in camera coordinates as 93 875 P2 48 775 mm 772 927 and the camera is located in room coordinates at 364 776 Pz 233 388 mm 648 903 The UpdateHomogeneousTransforms utility accepts 3 arguments UpdateHomogeneousTransforms MarkerIDNumber RCMode VTMode where MarkerIDNumber is the marker ID number RCMode is the room coordinates mode VMMode is the virtual marker mode The valid values for RCMode and VTMode are 0 1 2 and 3 as described in the next section In the example invocation above the marker ID number is 112 RCMode is 2 and VTMode is 1 Revised Mar 17 2013 Page 36 MPT Users Manual Section 4 3 2 Detailed User Manual Notes Transforms 7T and T are recorded in the marker context in shared memory which is created the first time a marker is processed by TrackMPT Marker So a marker must be processed at least once by TrackMPT Marker before UpdateHomogeneousTransforms can be used to set T or JT Marker ID number 112 is used in the examples that follow Substitute the actual marker ID number for 112 4 3 2 1 Modes used with the UpdateHomogeneousTransforms utility The 2 7 and 3 4 arguments to UpdateHom
24. 3 Page 6 MPT Users Manual Section 2 2 5 Quick Start Guide The LaunchProtectedXterms creates two shielded CPU cores and launches an xterm in each creating two shielded core windows as seen in figure 6 A processes started in one of these windows will be effectively the only process using the corresponding CPU core providing reliable real time performance 2 4 Bringing up the MPT Camera Images are transferred from the MPT Camera to computer memory by program CameraDaemonFW CameraDaemonFW may be launched using a non shielded core To activate the MPT camera navigate to the Metria Software MPT TrackingSystem bin directory user Bolt II cd Metria Software Scripts MPT TrackingSystem bin Launch program CameraDaemonFW user Bolt II bin CameraDaemonFW options For example user Bolt II bin CameraDaemonFW vpg F 50 E 123 CameraDaemon is configured via command line options that are described fully in section 4 1 The command line options in the example above are Vi Verbose option causes CameraDaemon to display status and diagnostic messages p Preview Window option launches an image preview window that will display the current captured image g Graphics option launches a window for graphical display of measurement data x y Z pitch roll yaw F50 The frame rate will be set to 50 fps E 123 The exposure time to 123 us The values of 50 fps and 123 us are used here as examples See s
25. 8 MPT Users Manual Section 4 4 2 Detailed User Manual 4 3 3 Common forms of the UpdateHomogeneousTransforms command The UpdateHomogeneousTransforms command has 16 variations Common forms are described here 4 3 3 1 Set room coordinates from a file To set room coordinates from a file and set virtual marker coordinates to the physical marker use the command user Bolt II bin UpdateHomogeneousTransforms 112 3 1 4 3 3 2 Set room coordinates to the current marker position To set room coordinates to the current marker position and set virtual marker coordinates to the physical marker use the command user Bolt II bin UpdateHomogeneousTransforms 112 2 1 4 3 3 3 Setting a virtual marker location With the command user Bolt II bin UpdateHomogeneousTransforms 112 0 2 the virtual marker position is set to the current room coordinates A process to set the virtual marker at known relation to the physical marker would be 1 Position the marker in a first position and set room coordinates to this location with the command user Bolt II bin UpdateHomogeneousTransforms 112 2 1 4 4 Additional real time display information 4 4 1 Measurement of Starburst brightness The mean intensity of the white area of the starburst is passed out as the value LMIntensity This is available as the 4th field of the first landmark record in the B log file and through the real time display as described in section 4 4 3 4 4 2 Measuremen
26. 802 68 4233 32 FrameNumber 0 123 MarkerLocation 0 1154 0149 Col Row FrameNumber 1 124 MarkerLocation 1 1164 0159 Col Row EstimatorData nSamples 400 MarkerData 23 bCaptureRoomCoordinates FALSE MarkerData 23 crT 1 000000 0 000000 0 000000 0 000 0 000000 1 000000 0 000000 0 000 0 000000 0 000000 1 000000 0 000 0 000000 0 000000 0 000000 1 000000 MarkerData 23 rcT 1 000000 0 0 000000 0 0 0 000000 1 000000 0 000000 0 000 0 000000 0 000000 1 000000 0 000 Revised Mar 17 2013 Page 49 MPT Users Manual Section 4 9 3 Trouble Shooting 0 000000 0 000000 0 000000 1 000000 MarkerData 23 bCaptureVirtualMarker FALSE MarkerData 23 vtT 1 000000 0 000000 0 000000 0 000 0 000000 1 000000 0 000000 0 000 0 000000 0 000000 1 000000 0 000 0 000000 0 000000 0 000000 1 000000 MarkerData 23 tvT 1 000000 0 000000 0 000000 0 000 0 000000 1 000000 0 000000 0 000 0 000000 0 000000 1 000000 0 000 0 000000 0 000000 0 000000 1 000000 MarkerDataMutex 1 Kockckckckck ck ck ck kk k kk kk kkk Interpreting Mutex value ockckckckckck ck ck kc ck k ck k kkkkkk kk kk kk Mutex value Positive Value No threads waiting 0 Threads waiting Negative Value Count of Threads Waiting 4 9 2 ReadInterruptTime There is a utility availab
27. Moir Phase Tracking System User Manual Model MT 384ib Metria Innovation Inc Moir Phase Tracking System User Manual Model MT 384ib Metria Innovation Inc Copyright c 2010 2013 Metria Innovation Inc All rights reserved Moir Phase Tracking and MPT are trademarks of Metria Innovation Inc Contents 1 Introduction 1 1 Overview of this manual 2 Quick Start Guide 2 1 22 Starting the MPT hardware Cabling nos e OP eee 2 1 2 Logging in to the Bolt II MPT processing computer 2 1 3 Energizing the MPT Camera Lighting Starting the MPT Software 2 1 1 221 222 223 2 2 4 2225 Automatic MPT software startup Exiting MPT software following automatic startup Manual startup 2 2 3 1 Setting up shielded cores for MPT processing Bringing up the MPT Camera Bringing up the moir phase tracking software 3 Theory of Operation 3 1 3 2 3 3 3 4 3 5 Real time Moir Phase Tracking 3 1 1 3 1 2 3 1 3 3 1 4 3 1 5 3 1 6 3 1 7 3 1 8 3 1 9 Basics of POSIX shared memory and message queues aM Aes d ut n iE ag 11 ocn ofr d rer eo cate 11 iow deos 12 Operation of CameraDaemon GrabImage 3 1 3 1 CameraDaemon saves the ring when tracking is lost TR uM Ra aaa 12 y a y a TITI IT IS 12 filed ede uide Dee o e dene 13 A d d Re eri res re do ca ed 14 STRICT 14 pace oce due dece oe ere E 15 bc a e a erai e rs ec ee a 16 Marker Context Marker tracking and prediction The cosine amb
28. Starburst spoke that is aligned with a circular landmark see figure 17 The bits are then read out starting at the 11 30 position most significant bit and proceeding counter clockwise That is 9 30 8 30 6 30 5 30 3 30 2 30 12 30 least significant bit Black triangles correspond to the binary value 0 and white triangles correspond to the binary value 1 Revised Mar 17 2013 Page 47 MPT Users Manual Section 4 9 1 Detailed User Manual For example the Marker ID Number in figure 17 is read 0001 1010 This is the binary code for the decimal value 26 i e Marker ID 26 Bit7 BitO Figure 17 An MPT image with marker showing the bar code for Marker ID 26 4 9 Additional utility commands There are several additional commands available in an MPT system installation 4 9 1 ShowSharedMemoryState ShowSharedMemoryState is an MPT utility that attaches to the shared memory of a currently running set of CameraDaemonFW TrackMPT Marker processes and displays shared memory state data Example data is illustrated below The shared memory state includes information about the ring buffer described in section 3 1 2 and the marker context described in section 3 1 4 user Bolt II bin ShowSharedMemoryState ShowSharedMemoryState pSharedMemory 7fdcba326000 AttachTime 0 sizeof SharedMemoryRecord t 9089600 Shared Memory Content bNotify 20 9 bSaveRing 0 bDoSaving 0 bStop 0 bSaveCropped 0 Revised
29. a TrackMPT Marker process is ready it will be started as soon as an image becomes available in the CameraDaemon ring buffer minimizing temporal jitter Revised Mar 17 2013 Page 11 MPT Users Manual Section 3 1 6 Theory of Operation 3 1 3 1 CameraDaemon saves the ring when tracking is lost CameraDaemon detects a period of active image transfers via GrabImage followed by a halt in image transfers Exploiting the ring buffer architecture of figure 7 when a halt in image transfers is detected CameraDaemon saves nRingNodes 1 images to disk in the Metria Logging directory as described in section 4 6 This feature can be disabled the default is enabled with the r option to CameraDaemon A period of active image transfer is defined as more than GrabThreshold consecutive transfers via GrabImage Parameter GrabThreshold is setin file ConfigRunTime xml see section 7 2 3 1 4 Marker Context An MPT Marker Context is a data record in shared memory that is accessed by TrackMPT Marker processes The marker context is specific to the Marker ID Number and all TrackMPT Marker processes processing a specific marker access the marker context of that marker Communication with the marker context is illustrated in figure 8 The marker context supports Tracking so each TrackMPT Marker process benefits from the most recent tracking information available in all TrackMPT Marker processes Estimation so each TrackMPT Marke
30. am TrackMPT Marker called logging Status Frame Number Marker ID Number Number of landmarks located with pHinting nh and full search nf pHint location P R a 6 vector distance in meters no filtering or estimation IR a 6 vector distance in meters no filtering or estimation Ze R The estimated value of range Additional diagnostic engineering data The B logging file has 48 data fields and 17 labels Logging of the B logging data to disk is controlled by ConfigRunTime xml parameter bEnableLogB LoggingMessages see table 3 4 6 2 1 Time tags in the B log file During processing of each image in TracKMPT Marker four time tags are recorded l FrameTime is provided by the drive camera For the AVT Stingray F033B firewire camera FrameTime corresponds closely within microseconds to the end of the exposure ImageAcquired this time tag is recorded when the image becomes available to CameraDaemon ImageGrabbed this time tag is recorded when the image is received by TrackKMPT Marker and processing begins UDPPacketSent this time tag is recoreded after the return from the function which calls linux send to send the UDP packet Note UDPPacktSent time is recorded upon return from the callor of send it is possible that there is additional linux buffering before the packet hits the wire Revised Mar 17 2013 Page 44 MPT Users Ma
31. as does rebooting the computer 3 1 2 Operation of CameraDaemon The CameraDaemon process launches several threads including the Camera thread Preview thread Graphics thread and MPT Logging Server thread The threads execute independently The camera thread communicates with the camera setting the camera configuration and receiving images When an image is received these steps are executed The image is transferred to the next node on the Ring Buffer which is seen in figure 7 A message is sent to the GrabImage message queue where the image can be consumed by a waiting TrackMPT Marker process f previewing is active a message is sent to the preview thread to indicate that an image is available 3 1 3 GrabImage Function GrabImage provides images to the running TrackMPT Marker processes and provides synchronization to the stream of images An TrackMPT Marker process posts a read on the GrabImage message queue This read will wait until an image is available If there is an unprocessed image at the head of the ring buffer GrabImage returns the image immediately If the last image on the ring buffer has already been accessed GrabImage will wait for a new message on the GrabImage queue For example in figure 7 if processes TrackMPT Marker l and TrackMPT Marker 2 are configured to process the same marker the TrackMPT Marker GrabImage mechanics will insure that each image is processed only once Additionally if
32. center of the frame exposure The frame time stamp is given by frameTime Tframe arrival frameDelay uS where Tframe arrival is the Bolt II system wide clock time when CameraDaemon received the frame frameDelay us is a value loaded from ConfigRunTime xml and can be used to offset T rame arrival to the end of the exposure x GC 650 gigabit ethernet camera a frameDelay_uS value of 10393 us has been calibrated for a operating at maximum frame rate Stingray F033B firewire camera a frameDelay_uS should be set to zero for the the firewire camera driver provides the exposure time as measured by the Linux clock in the low level image data structure 2 Interrupt Time Stamp irqTime This is the time of the last externally triggered event detected by the Interrupt Time Stamp driver irgTime Tirq registered irqDelay u where irqTime is the time of externally triggered event to Tirq registeredisthe time the MPT computer recorded the interrupt irgDelay uS is the time delay from the rising edge of the interrupt to registration of Tirq registered irqSequenceNum is a counter that is incremented each time an interrupt is received The default value of 8 us listed listed in section 7 2 has been calibrated for a Bolt II computer Revised Mar 17 2013 Page 15 MPT Users Manual Section 3 3 0 Theory of Operation 3 2 UDP packet format The UDP packet format version 3 is listed Integers Unsigned Int
33. cond TrackMPT Marker instance can run on the same or a different tracking marker If the second TrackMPT Marker instance runs on different Marker ID Numbers the two TrackMPT_Marker processes will process each image and report their respective measurements If the second TrackMPT Marker instance runs on the same Marker ID Number the two TrackMPT_Marker processes will process alternate images permitting tracking at high frame rate To stop TrackMPT Marker type lt ctrl c gt in each processing window ctrl c See section 4 2 for additional information regarding TrackMPT Marker execution Revised Mar 17 2013 Page 8 MPT Users Manual Section 3 1 1 Theory of Operation 3 Theory of Operation The theory of operation of the MPT system is described in this section Real time moir phase tracking described in section 3 1 followed in subsequent sections by discussion of UDP packet generation logging and other specific aspects of moir phase tracking The basic steps of processing an MPT marker image are 1 Detect and locate the starburst landmark 2 Detect locate and classify the four circular landmarks 3 Make an initial estimate of the marker pose PoseHat 1 based on the five landmark locations in the image 4 Using the PoseHat1 read the moir patterns and fit a sinusoidal function to the intensity pattern 5 Using the moir pattern phases landmark locations and PoseHat 1 estimate the marker p
34. d at the time TrackMPT Marker is launched It is specified either on the command line or in file ConfigRunTime xml When a marker model is sought function LoadMarkerModel examines the collection of models in the marker series starting with the first listed MarkerSeriesNumber and continuing until the marker model is located or all MarkerSeriesNumbers have been examined The Marker ID number is an 8 bit code so up to 256 markers can be included within each marker series Specifying the marker series numbers in file ConfigRunTime xml Fields lt MarkerSeriesNumbers gt 1001 1015 1016 lt MarkerSeriesNumbers gt specifies the marker series numbers see section 7 2 Sequare brackets are permitted so the MarkerSeriesNumbers can be given as lt MarkerSeriesNumbers gt 1001 1015 1016 lt MarkerSeriesNumbers gt Revised Mar 17 2013 Page 46 MPT Users Manual Section 4 8 4 Detailed User Manual The maximum number of MarkerSeriesNumbers is equal to the maximum number Markers that can be tracked Any MarkerSeriesNumbers past the maximum will be ignored Specifying the marker series on the command line with the S switch The primary marker series number can be specified using the S switch when TrackMPT Marker is launched For example the line user Bolt II bin TrackMPT Marker S 1015 specifies that marker series 1015 is to be used as the primary marker series number over ridding the value given in t
35. e 4 Spherical marker coordinates 5 Spherical marker coordinates and Q replaced with PY and PX of the Starburst landmark location 6 Spherical marker coordinates Append screen message if the Cosine Ambiguity is recovered 7 Spherical marker coordinates Last value is Starburst intensity 8 Spherical marker coordinates Last value is Starburst focus Table 1 Table of alternative display modes marker is in a region that will activate Cosine Ambiguity Recovery Mode 7 can be used to adjust the lighting intensity and mode 8 can be used to adjust focus see sections 4 4 1 and 4 4 2 The alternative display modes are listed in table 1 For example mode 5 can be used to plot and stream the landmark location in pixel coordinates Mode 6 can be used to observe whether the marker is in a region that will activate Cosine Ambiguity Recovery Mode 7 can be used to adjust the lighting intensity and mode 8 can be used to adjust focus see sections 4 4 1 and 4 4 2 Revised Mar 17 2013 Page 41 MPT Users Manual Section 4 6 0 Detailed User Manual 4 4 4 Plotted data statistics When graphing is activated the addition of the G switch to CameraDaemon user Bolt II bin CameraDaemonFW gG Will cause CameraDaemon to report statistics on the streaming data values each time the graph is refreshed Example data is illustrated below The statistics correspond to the graphed data cf figure 15 The data labels c
36. e uS dE 29 422 Filter and estimator 2 en den a XT RETE TUER S RUE we 29 4 22 1 Optional 5 order discrete filtering of samples 29 TrackMPT_Marker streaming output 32 4 3 1 Available coordinate frames for streaming output 34 4 3 2 Setting T and T with UpdateHomogeneousTransforms 35 4 3 2 Modes used with the UpdateHomogeneousTransforms utility 37 4 3 3 Common forms of the UpdateHomogeneousTransforms command 39 4 3 3 1 Set room coordinates from a file 39 4 3 3 2 Set room coordinates to the current marker position 39 4 3 3 3 Setting a virtual marker location 39 Additional real time display information 39 44 1 Measurement of Starburst brightness 39 4 4 2 Measurement of Starburst focus 39 4 4 3 Activating real time display modes with UpdateHomogeneousTransforms 40 4 4 3 1 Example activating display in spherical marker coordinates 40 4 4 4 Plotted data statistics os d ue d epo se d equ Lee DAS VER 42 User editable parameter files 1 2240 o 9 os ey y RR 42 IBS dr PROMIT EE EK Rec ee 42 4 6 1 Fields of the A logging file 43 4 6 2 Fields of the B logging file uuu ewe a 44 4 6 2 1 Time tags in the B log file 44 4 6 3 Checking the fill level of the MPT logging partition 45 MPT Lighting Sy
37. each image taken by the camera is set in ConfigRunTime xml or using the E option This option is specified in microseconds The camera has upper and lower limits corresponding to this value If set out of range a message will be produced and the value will be coerced into the acceptable range for the camera user Bolt II bin CameraDaemonFW E 700 An additional limit on the exposure time is placed by the thermal protection logic within the lighting system Depending on the light level setting and the camera flash duty cycle the protection logic may shut the lighting system down when it encounters a flash that exceeds the thermal protection limit Preview window The Preview Window displays images acquired by the camera The Preview Window refresh rate is typically less than the camera frame rate it skips images to always display the most recent frame The preview window is activated with the bShowPreviewWindow parameter in ConfigRunTime xml or the p option user Bolt II bin CameraDaemonFW p 4 1 7 1 Hot keys that operate in the preview window Several keys are detected when they are typed into the preview window These provide mechanisms that can be selected while CameraDaemon is running They are activated by typing the corresponding keystroke in the preview window i Show intensity Analyze the image and report the value of the brightest pixels and the number of pixels at that brightness Pressing the hot key t
38. ection 5 for a discussion of exposure and light level To stop CameraDaemon type ctrl c in the terminal window where it was started or press the q key in the preview window ctrl c Revised Mar 17 2013 Page 7 MPT Users Manual Section 2 2 5 Quick Start Guide 2 25 Bringing up the moir phase tracking software To activate moir phase tracking use one of the black shielded core window created by LaunchProtectedXterms Using the shielded core navigate to the bin directory user Bolt II cd Metria Software Scripts MPT TrackingSystem bin Launch program TrackMPT Marker user Bolt II bin TrackMPT Marker options Program TrackMPT Marker option examples user Bolt II bin TrackMPT Marker user Bolt II bin TrackMPT Marker T 25 user Bolt II bin TrackMPT Marker T 25 S 1021 where 1021 and 25 are the Marker Series Number and Physical Marker ID Number of a marker See section 4 8 for a description of marker numbering TrackMPT_Marker should now be running as illustrated in figure 6 To run a second TrackMPT_Marker process use the second shielded core window and launch a second instance of program TrackMPT_Marker In the second shielded xterm change directory to the MPT system executable directory user Bolt II cd Metria Software Scripts MPT_TrackingSystem bin Launch TrackMPT Marker user Bolt II bin TrackMPT_Marker options The se
39. egers and floating point numbers are 32 bits A value of status 0 indicates a valid reading define CURRENT PACKET VERSION NUMBER 3 typedef struct UDPPacketDef s int PacketVersionNumber int status int MarkerIDNumber formerly TargetIDNumber int FrameNumber float x Y Z z is filtered float qr quaternion real part ud qx quaternion vector part qy qz unsigned int frameTime_sec unsigned int frameTime_nsec unsigned int irqSequenceNum unsigned int irqTime sec unsigned int irqTime nsec loat tSScknot 6 loat tZcknotHat loat xHat x y z based on the estimated sZ Hh Hh Hh yHat zHat UDPPacket t 3 3 The session directory for logging Every time CameraDaemon is launched it creates a new session directory at the path Metria Logging Session Session Date amp Time where Session Date amp Time is a unique identifier based on the date and time of the CameraDaemon activation For example Revised Mar 17 2013 Page 16 MPT Users Manual Section 3 4 2 Theory of Operation Metria Logging Session 2010 11 03 17 17 49 Metria Logging Session 2010 11 03 17 17 09 When loaded the shell function GoToMostRecentMPTSession will take the current working directory of a shell to the most recent session directory For example user Bolt II GoToMostRecentMPTSession userQBolt II Session 2010 11 03 17 17 49 S 3 4 Maximu
40. false True enables Cosine true false Ambiguity Recovery see section 3 1 6 NearTDCThreshold 10 0 CAR parameter 0 90 PoseHat1 RejectCycles 0 3 CAR parameter 0 1 nMinGoodFramesToActivate 5 CAR parameter 0 and up nBadFramesToDeactivate 5 CAR parameter 0 and up nMaxFrameNumberGap 10 CAR parameter 0 and up Table 6 Significance of ConfigRunTime xml entries continued Parameters controlling Cosine Ambiguity Recovery 7 2 6 Find starburst parameters The starburst landmark is the robust landmark at the center of the MPT marker Its detection is controlled by these parameters These parameters are generally not user adjustable Field Name Example Significance Allowed Values Data StarburstRadius 5 5 Radius used to detect 5 5 9 5 pixels Starbursts StarburstStepFactor 0 3 Starburst parameter 0 3 StarburstMaxTilt 60 Starburst parameter 0 60 degrees StarburstMinGapPixels 1 5 Starburst parameter 1 5 StarburstHintClickRadius 10 Starburst parameter 0 10 pixels StarburstPreSearchIntensityThreshold 20 Starburst parameter 0 255 intensity StarburstPreSearchCountThreshold 6 Starburst parameter 6 StarburstPreSearchPaddingCount 6 Starburst parameter 6 Table 7 Significance of ConfigRunTime xml entries continued Parameters controlling Starburst detection Revised Mar 17 2013 Page 63 MPT Users Manual Section 7 4 0 Appendices 7 2 7 Comments in xml files Co
41. g partition is full is checked and compared with value AllowedLoggingDirectoryLevel from file ConfigRunTime xml see section 7 2 If the logging partition is over full the user is given the options of purging the logging directory or exiting User options are Select purge which deletes all contents of partition Metria Logging In this case all contents of the logging partition are deleted 2 Exit TrackMPT Maker and selectively delete files from the logging partition 3 Exit TrackMPT Maker and adjust parameter AllowedLoggingDirectoryLevel in file ConfigRunTime xml Revised Mar 17 2013 Page 45 MPT Users Manual Section 4 8 2 Detailed User Manual 4 7 MPT Lighting system The MPT lighting system includes power electronics and an LED Power is provided through a BNC connector on the back of the MPT Camera and Lighting Unit The supply voltage should lie on the range XX lt V lt XX volts with shell as ground and pin as Vs 4 5 MPT marker ID numbers 4 8 1 MPT marker ID number and Marker series number For accurate tracking each moir phase tracking marker must be associated with its specific calibration information Calibration files are stored in directory Metria Software MPT TrackingSystem ParamFiles The MPT marker calibrations are stored by two numbers Marker Series Number Physical Marker ID Number 4 8 3 Marker series number The marker series number to use must be specifie
42. he configuration file 4 8 3 Marker ID number Each moir phase tracking marker has a unique 8 bit ID number encoded in eight regions on the marker This permits 256 unique marker ID numbers on the range 0 255 Marker ID number 256 is reserved for a generic marker model with each marker series Specifying the marker ID number in file ConfigRunTime xml Field lt PhysicalMarkerIDNumber gt 128 lt PhysicalMarkerIDNumber gt specifies the marker ID number of the marker to track see section 7 2 Specifying the marker series on the command line with the T switch The marker ID number can be specified using the T switch when TrackMPT Marker is launched For example the line user Bolt II bin TrackMPT Marker T 115 specifies that marker 115 is to be used over ridding the value given in the configuration file Automatic marker ID number detection Additionally the marker ID number can be automatically detected for one marker in the images see section 3 1 8 Using this technique TrackMPT Marker can be initialized with any valid marker ID number such as 256 4 8 4 Reading the MPT Marker ID number The Marker ID Number is read from each marker in each image providing unique identification and the ability to unambiguously track multiple markers The Marker ID Number is encoded in black and clear white triangular marks at the perimeter of the generation VII MPT marker Place the marker in the zero roll position by finding the one
43. hen loading images from disk the w options is used to throttle the images so each image gets processed user Bolt II bin CameraDaemonFW pgw D tmp Images e The l option will cause CameraDaemon to loop through a set of image files continuously user Bolt II bin CameraDaemonFW pgl F 80 Also notice that options can be listed individually and in any order be changed to D tmp Images The example above can user Bolt II bin CameraDaemonFW F 80 p g 1 D tmp Images Revised Mar 17 2013 Page 27 MPT Users Manual Section 4 2 0 Detailed User Manual 4 2 TrackMPT Marker Program TrackMPT Marker processes images to produce measurements It is launched as described in sections 2 2 The broad theory of operation is given in section 3 1 3 Details of using program TarckMPT Marker are provided here The basic processing cycle of TrackMPT Marker is illustrated in figure 14 Grablmage Provides Image and Predicted Target Location Look for Target in Neighborhood of Predicted Target Location Is Target Identified No Yes Yes x Is Target Identified Register target location for next prediction Process the Target Target Pose Measured Successful Measurement Yes Run the Filter and Estimator Process Entire Image Searching for the Target No UDP Packet emitted Diagnoistic Information Status
44. i seconds Loss of tracking can be caused by fast motions or marker obstruction When marker motion returns to an acceptable level tracking will resume 4 2 2 Filter and estimator Two methods are provided to filter pose values or to estimate pose values 1 A 5 order digital filter 2 An estimation algorithm MPT is very accurate for orientation and 2 elements of position but relatively less accurate for the distance of the camera marker separation which is written Ze and is typically estimated with an accuracy of 1 2 000 the camera marker separation The 5 order digital filter can now be applied to all 6 pose elements in Camera Cartesian coordinates P See section 7 1 for definition of the elements of pose vector P 4 2 2 1 Optional 5 order discrete filtering of samples A 5 order discrete time filter is applied to each component of pose vector P That is to say six parallel 5 order filters are run The filter mechanism combined with parameters in Revised Mar 17 2013 Page 29 MPT Users Manual Section 4 2 2 Detailed User Manual Metria Software MPT TrackingSystem ConfigRunTime xml provides these capabilities e Set the filter parameters Enable Disable filtering for each element of P individually Control when the filter state is initialized The filter is implemented according to Wout k A 2 Wou k 1 A 6 Wout k 5 6 B 1 win k 4 B 6 win k
45. iguity recovery mechanism Accelerated Starburst detection Automatic detection of Physical Marker ID Number Frame and Interrupt time stamps UDP packet format The session directory for logging Maximum range and required image size for moir phase tracking LS 17 P NA TE A RE eM 17 y One xoc we doct Beas Baan Te Ge Ted oe 18 3 4 1 Measurement coordinate frames Maximum range 3 4 2 Range and tilt fore shortening of the MPT marker 4 Detailed User Manual 4 1 Camera Daemon 4 1 1 Basics of Camera Daemon RTE ES oe ee Sek 16 m I7 Revised Mar 17 2013 Page i 4 2 4 3 44 4 5 4 6 4 7 4 8 4 2 CameraDaemon help message 21 Z3 0 SEDOSIDIO ao hcec iic qa pnt oe oe Tet S Re ee eh to TE e Bo 22 4 1 4 Frame Rate and Under Sample 22 4 1 5 Image save count and image save rate 22 ANG EXpos re 2 a RS e CUR rub ne Da me 23 JT b Preview WIBUOW Le si vais uw NON NES NARNIA SS 23 4 7 1 Hot keys that operate in the preview window 23 4 1 7 2 Preview and Graphing Window Marking 25 4 1 8 Graphing a continuous plot of the MPT marker pose 26 4 1 9 Loading images from disk odors eR D Pe Bes See EES ERE YD 26 4 1 10 Examples of typical CameraDaemon usage 27 TrackMPT Market Acura y Side S049 Mey NS TR SUPE REN SCPTN RUNS ARS A 28 AZA Performance os ea doe ee x Ee Bs d
46. ion of the marker ID number see section 3 1 8 nSuccessful 3 Number of times a marker 1 221 1 FindsFor must be seen for automatic AutoDetect detection Table 3 Significance of ConfigRunTime xml entries continued Revised Mar 17 2013 Page 60 MPT Users Manual Section 7 2 3 Appendices 7 2 3 Camera daemon parameters displayed and graphed data Field Name Example Data Significance Allowed Values Exposure 400 Camera exposure in 1 1000000 micro seconds FrameRate 82 0 Camera frame rate 1 84 9 bShowPreviewWindow true Open the preview window true false on startup bShowGraphingWindow false Open the graphing true false window on startup ImageSaveCount 200 Number of images to save Limited by system when the save image RAM mechanism is triggered see sections 4 1 7 1 ImageSaveRate 2 0 Frame rate at which to 0 FrameRate save images see section 4 1 5 EKG RedrawlInterval 0 1 Time interval to update Useful range is data in the streaming plot lower bounded by the graphic seconds refresh rate No upper see section 4 1 8 limit EKG XaAxisPeriod 20 Period of the X axis of the Period is limited by streaming plot graphic the sample rate and seconds EKG buffer size of 1200 samples InitialDisplayMode 1 Initial display mode for 0 8 see section 4 4 3 and table 1 Table 4 Significance of ConfigRunTime xml entries continued
47. ker is re acquired Additional Notes on Filtering UDP packet The values in the UDP packet are listed in section 3 2 Filtered values are inserted into the UDP packet as the x y z and qr qx ay az coordinates Revised Mar 17 2013 Page 31 MPT Users Manual Section 4 3 0 Detailed User Manual Rotations Since filtering the individual quaternion components would require 7 rather than 6 values and would result inconsistent quaternion vectors the orientation is expressed as Euler angles for filtering corresponding to 0 0 0 in Eqn 7 The filtered rotation is computed according to 1 0 0 Quaternion FR with eR 0 1 0 R R R 8 0 0 I where TR is the rotation T based on the current filtered values of the Euler angles which give R R and R See Eqn 17 in section 7 1 for an explanation of the 180 degree yaw rotation in Eqn 8 This filter operates in each MPT process independently 4 3 TrackMPT Marker streaming output TrackMPT Marker has two streaming display mechanisms that permit real time monitoring of the measured data 1 Streaming text data to the terminal An example of streaming data is seen in figure 15 Each line includes Camera frame time FT Status S Marker ID number M and camera frame number F Note For convenience the frame time is adjusted to show the time since CameraDaemon was started X Y Z pitch roll yaw the current pose of the MPT marker 2 G
48. le to get the last time value made available by the Interrupt driver user Bolt II KernelModules ReadInterruptTime Sequence number 1310 tv_sec 1277148304 tv_nsec 876433735 priority 80 4 9 3 TagDRTLogFile Log file tagging As TrackMPT_Marker is running it creates log files as described in section 4 6 The shell script Utility TagDRTLogFile permits tagging a log file so that the readings corresponding to a specific event can be located 4 9 3 1 Creating a tag file For example these three calls to TagDRTLogFile create 3 entries in the file Tags DRTLogFile txt in the session directory where the DRTLog files are created see section 3 3 user Bolt II MPT TrackingSystem TagDRTLogFile This is a first tag Tagged frame number 13675 to tag file directory in Metria Logging Session 2010 10 05 15 48 03 Tags DRTLogFile txt user Bolt II MPT TrackingSystem TagDRTLogFile This is a second tag Revised Mar 17 2013 Page 50 MPT Users Manual Section 4 9 3 Trouble Shooting Tagged frame number 13720 to tag file directory in Metria Logging Session 2010 10 05 15 48 03 Tags DRTLogFile txt user Bolt II MPT TrackingSystem TagDRTLogFile This is a third tag Tagged frame number 13760 to tag file directory in Metria Logging Session 2010 10 05 15 48 03 Tags DRTLogFile txt The entries in file Tags DRTLogFile txt in the session directory will be user Bolt II Session 2010 10 05 15
49. m range and required image size for moir phase tracking 3 4 1 Maximum range The maximum range for marker tracking is defined by two effects Focus and depth of field and Minor radius of the ellipse enclosing the starburst MPT is robust to several pixels of blur but blur at the level of 4 5 pixels will prevent processing of the marker The minor radius of the ellipse enclosing the starburst landmark must be at least 11 pixels The landmark is foreshortened by tilt and so the maximum geometric range is greater when the marker is in near normal orientation to the camera and becomes less as the tilt increases 3 4 Range and tilt fore shortening of the MPT marker The image of an MPT marker is fore shortened by tilt as seen in figure 9 The tilt angle is given by 0 cos Zi Zi 1 where Zz iy Z a is the inner product of the camera and marker unit Z axis vectors Figure 9 Illustration of marker 006 nearly straight on and at 40 degrees of tilt Revised Mar 17 2013 Page 17 MPT Users Manual Section 3 5 0 Theory of Operation The degree of fore shortening determines the required pixel footprint of the marker in the image Tilts up to 60 are accommodated when the image resolution would provide 65 pixels along the nominal length of one edge of the marker For example Nominal marker size Li 20mm Camera Resolution sy 0 0074mm pixel Distance L 2800mm Effective Lens Length cp 70 0mm gives
50. m using mode 2 is user Bolt II bin UpdateHomogeneousTransforms 112 2 1 which sets JT to the identify matrix and sets room coordinates to the current marker coordinate frame Notes Since Eqns 13 and 14 can not be applied simultaneously command user Bolt II bin UpdateHomogeneousTransforms 112 2 2 is disallowed and invokes an error message Commands of the form user Bolt II bin UpdateHomogeneousTransforms 112 2 x or user Bolt II bin UpdateHomogeneousTransforms 112 x 2 where x is one of 0 1 3 always execute the non mode 2 function first Thus for example user Bolt II bin UpdateHomogeneousTransforms 112 2 1 first sets T to the identity matrix then sets T according to Eqn 13 3 Load T or T from file Command user Bolt II bin UpdateHomogeneousTransforms 112 3 0 loads T from file RoomCoordinatesHT txt Command user Bolt II bin UpdateHomogeneousTransforms 112 0 3 loads T from file VirtualMarkerHT txt Each file specifies a pose with data of the form Any lines starting with a hash are comments and will be ignored 55 630 39 576 2279 918 0 374664 0 895269 0 2254967 0 085259 where the first three values are XYZ and the last 4 values specify the rotation as a quaternion with the vector portion in parentheses and the real component of the quaternion at the end Note the position variables are in mm Revised Mar 17 2013 Page 3
51. mments in xml files have the format A Comment gt So material of the form res lt Bfilter gt 100000 lt Bfilter gt lt Afilter gt 100000 lt Afilter gt gt is commented out and material without the bracket is included 7 3 Calibration data 7 3 1 Measured latencies e End of exposure to receipt of image time T rame arrival in section 3 1 9 for AVT Prosilica GC 650 camera 10939 us Rising edge of the external timing signal to Tirg registered time 8 us 7 4 Setup checklist This checklist is for confirming the correct setup and configuration of MPT Check for correct 1 Configuration mirror status IP address etc 2 Camera model 3 Marker models 4 Check voltage at the CLU Revised Mar 17 2013 Page 64
52. n 1 00 Used by Metria CameraName AVT Name and serial number As given changed StingrayF033B of the MPT camera only if the CLU is XX exchanged LensName UKA9mmf8 Name of the lens type UKA9mmf8 UDPHost 192 168 1 1 Destination of the UDP Any valid IP address packets UDPPort 22222 Port number to which Any valid IP port UDP packets are sent number PhysicalMarker 192 ID Number of the default 0 256 IDNumber marker Marker 1001 1015 Marker series numbers to Provided by Metria SeriesNumbers search when loading a marker model jMirror 1 jMirror gt 0 indicates that a 1 for the CLU 384ib mirror is used SharedMemory 4100 Used by Metria BaseKey GrabThreshold 100 Number of valid MPT data 1 251 1 reads to activate the save ring mechanism see section 3 1 3 1 Table 2 Significance of ConfigRunTime xml entries Significance of parameters of the basic run time configuration Revised Mar 17 2013 Page 59 MPT Users Manual Section 7 2 2 Appendices 7 2 2 Overall MPT system parameters Overall MPT system parameters are listed in table 3 Field Name Example Data Significance Allowed Range or Values AllowedLogging 0 850 Maxim fill fraction 0 0 0 99 DirectoryLevel allowed for the logging partition See section 4 6 bEnableLogB true Activate recording of the true false Logging B log file see section 4 6 Messages bEnableAuto true Activate automatic true false MarkerDetect detect
53. nates as P SR P P 18 where P j mm is the position of the marker expressed in camera coordinates In this notation transformations from one coordinate frame to another are written R or 7T where the left subscript indicates the frame the transformation is coming from and the left superscript indicates the frame the transformation is going to p4x4 and where R SO 3 R is a rotation matrix and T SE 3 transformation matrix is a homogeneous Rotations R Ry and R in Eqn 17 are the elementary rotations given by 1 0 CG 09S OEE 0 Ry a 0 Ci Sy Ry 0 1 0 R Sz C 0 19 Revised Mar 17 2013 Page 56 MPT Users Manual Section 7 2 0 Appendices where C and S are cos 0 and sin 0 C and S are cos 0 and sin 0 and C and S are cos 0z and sin 0 respectively and where 0 0 8 degrees are the Euler angles of the pose about the X Y and Z axes respectively The first rotation matrix in Eqn 17 gives a 180 y axis rotation corresponding to the Z axis being the optical axis of the camera and the Z axis being the optical axis of the marker Equation 17 gives the definition of the rotation matrix based on Euler angles for poses expressed in Cartesian Camera coordinates The homogeneous transform from marker to camera coordinates and thus the pose of the marker in camera coordinates is written as 10 0
54. nual Section 4 7 0 Detailed User Manual Time tags are recorded in the B log file in this way FrameTime Is given as a time in seconds since 12 00AM January 1 1970 UNIX time making the count of seconds a very large number The value is reported as lt seconds gt lt microseconds gt ImageAcquired ImageGrabbed UDPPacketSent These times are given as the difference relative to the FrameTime Each is give as 0 lt microseconds gt Example data FT 1362447858 302077 DIAT 0 012764 DIGT 0 013132 DUDPT 0 019129 FT 1362447858 314703 DIAT 0 012741 DIGT 0 013090 DUDPT 0 019268 FT 1362447858 327328 DIAT 0 012810 DIGT 0 013145 DUDPT 0 019678 FT 1362447858 339952 DIAT 0 012705 DIGT 0 013082 DUDPT 0 019205 DIAT is Delta Image Acquisition Time DIGT is Delta Image Grabbed Time DUDPT is Delta UDP Packet Sent Time In the example data each image spends 12 8 mill seconds for transfer from the camera to the computer and approximately an additional 7 milli seconds before the UDP packet is sent An unfortunate characteristic of the firewire interface is that the data rate 1s used to regulate the frame rate so the minimum transfer time is with no other latency 1 frame rate From the measured data the additional camera and O S latencies are about 1 milli second 4 6 3 Checking the fill level of the MPT logging partition Each time TrackMPT Marker is started the fraction that the loggin
55. ode Number 0 4 4 3 1 Example activating display in spherical marker coordinates For example when TrackMPT Marker is running on marker 22 the command user Bolt II bin UpdateHomogeneousTransforms 22 4 0 produces the result Processing Marker Number 5 22 Room Coordinate Mode 4 Spherical Marker Virtual Marker Mode 0 Do nothing Processing completed successfully and changes the streaming data display from Camera Cartesian coordinates standard FT 00007 686 S 00000 M 022 F 00000104 XYZPRY 0084 394 0057 752 2333 262 014 3255 052 7041 156 2580 T 00007 835 S 00000 M 022 F 00000105 XYZPRY 0085 011 0057 052 2331 898 014 0422 053 4041 156 0490 Hj To Spherical Marker coordinates FT 00004 123 S 00000 M 022 F 00000080 tSScknot 019 7064 021 3783 2341 413 0001 755702 0043 230 0001 624764 T 00004 269 S 00000 M 022 F 00000081 tSScknot 019 9587 021 1093 2341 300 0001 742157 0043 964 0001 648150 T 00004 413 8 00000 M 022 F 00000082 tSScknot 4020 2156 020 8812 2340 652 0001 730283 0044 643 0001 668977 Hj Hj The alternative display modes are listed in table 1 For example mode 5 can be used to plot and stream the landmark location in pixel coordinates Mode 6 can be used to observe whether the Revised Mar 17 2013 Page 40 MPT Users Manual Section 4 4 3 Detailed User Manual Mode Number Display coordinates Additional featur
56. of tSScknot TrackMPT Marker n Target Context 1 Starburst Tracking PCA Estimation Target Context n Figure 8 Block diagram of the real time MPT system showing marker contexts in shared memory 3 1 6 The cosine ambiguity recovery mechanism As describe at the beginning of section 3 in MPT processing an initial estimate of pose called PoseHat1 is determined from landmark locations In the region near top dead center where the line of sight from the marker to the camera is nearly perpendicular to the marker surface the estimation of PoseHat1 from the landmarks is poorly conditioned and there is considerable uncertainty in the initial estimate of the out of plane rotations This uncertainty plays only a small role in the subsequent reading of the moir patterns But if the error in the initial estimate of out of plane rotation 1s too great the final pose estimator may find an incorrect solution when matching the moir patterns To increase robustness in this region tracking information is used to further constrain the pose estimate The cosine ambiguity recovery mechanism compares the current estimates of PoseHat1 and PoseHat2 with tracking information and select a solution that is consistent with the tracking information The cosine ambiguity recovery mechanism can be activated or de activated by setting Revised Mar 17 2013 Page 13 MPT Users Manual Section 3 1 9 Theory of Operation
57. ogeneousTransforms determine how T and T are set respectively These arguments RCMode and VTMode can take the values of 0 1 2 or 3 0 Do nothing leave the transformation unchanged Note that both modes must be set at each invocation 1 Set the transformation to the identify matrix Thus the command user Bolt II bin UpdateHomogeneousTransforms 112 1 1 will return the streaming data for marker 112 to unmodified camera coordinates 2 Set the room coordinates to the current virtual marker pose or set the virtual marker pose to the current room coordinates Thus the command user Bolt II bin UpdateHomogeneousTransforms 112 2 0 will use the current measured pose to set the room coordinate transformation 77 according to pog 13 and will not change T This has the effect of setting the room coordinate frame to the current virtual marker location Similarly the command user Bolt II bin UpdateHomogeneousTransforms 112 0 2 will use the current measured pose to set the virtual marker transformation T according to wer ae 14 and will not change 7T This has the effect of setting the virtual marker frame to the origin of room coordinates Each form has the effect of giving E 0 0 0 1 0 0 0 o o Revised Mar 17 2013 Page 37 MPT Users Manual Section 4 3 3 Detailed User Manual which gives streaming readings of zero until the marker or camera is moved A common command for
58. oggles the display on and off I Show intensity II Render the image as a binary image showing only the brightest pixels Repeated keystrokes I rotates through 7 modes Revised Mar 17 2013 Page 23 MPT Users Manual Section 4 1 7 Detailed User Manual Show intensity II intensity threshold 100 of maximum intensity Show intensity IL intensity threshold 95 of maximum intensity Show intensity IL intensity threshold 75 of maximum intensity Show intensity IL intensity threshold 50 of maximum intensity Show intensity IL intensity threshold 25 of maximum intensity Show intensity II intensity threshold 12 5 of maximum intensity Show intensity II off Show intensity and Show intensity II will aid in setting the lighting level that maximizes MPT marker contrast without pushing the marker into pixel saturation J Terminate Show intensity II The J keystroke immediately shuts of Show intensity II m Toggle preview and graphing window marking q Quit This keystroke causes CameraDaemon to shut down r save Ring Provoke the save ring mechanism which writes images on the image ring buffer out to disk s Save images CameraDaemon can save nImagesToSave images to disk this is activated by typing s to the preview window While saving images the preview window will freeze and display Saving Images The number of images to be saved is controlled by the CameraDaemon run time pa
59. orrespond to the streaming data mode selected Graph Statistics Marker 0 nData 41 FrameNumber Std Deviation 213263 453958 650452 076637 726037 3131029 Az deg El deg SZ mm pitch deg roll deg SB Focus 4 5 User editable parameter files Mean 16 23 2343 1 35 1 943587 320455 953351 863844 816472 622146 OO HR a N One file contains user editable configuration data ConfigRunTime xml This file is described in section 7 2 4 6 Logging The MPT logging system produces 2 files 664 Minimum 12 21 2341 1 44 1 140349 013203 485840 738004 223183 385794 Maximum 20 045496 26 083660 2346 856689 1 997626 24 039875 1 969982 DRTLog_M lt Marker ID Number gt _ lt Creation Date and Time gt A log DRTLog_M lt Marker ID Number gt _ lt Creation Date and Time gt B log to Extremum 803238 763205 903338 133782 716597 347836 The A log file records measurement data The B log file records diagnostic engineering data These files contain text information so they can be opened in a text editor and examined Text data is stripped out with the UNIX bash script ReduceDRTLogFile which is run on the log file user Bolt II ReduceDRTLogFile DRTLog M023 2010 02 06 23 57 48A 10g and produces a data file such as DRTLog M023 2010 02 06 23 57 48A log dat Revised Mar 17 2013 Page 42 MPT Users
60. ose PoseHat2 6 Report results emit UDP packet and queue logging messages The next sections elaborate on some of the details 3 1 Real time Moir Phase Tracking In this section the detailed operation of the real time moir phase tracking system is described A block diagram giving an overview of the real time system is seen in figure 7 3 1 1 Basics of POSIX shared memory and message queues The POSIX software standard provides a range of inter process synchronization and communication tools Several aspects are discussed here that are important for understanding the operation of CameraDaemonFW and TrackMPT Marker Shared Memory Once a shared memory segment is created it is accessed by multiple processes using a commonly known key Each of the connected processes sees the shared memory segment The UNIX ownership and protection model applies and processes can connect with read or read write privileges A shared memory allocation persists until it is detached by all attached process Shared memory can be detached under program control for example during a clean shutdown or by terminating all attached processes Message Queues POSIX message queues can be used for both communication and synchronization Message queues have UNIX ownership and permissions Each message itself is a string of character data which can be cast to a structure type known to both the sender and receiver Revised Mar 17 2013 Page 9 MPT Users
61. owing marker contexts in shared NS RNC etae aa S RE TES ERR a aiT a aa a EE NE I3 Illustration of marker 006 nearly straight on and at 40 degrees of tilt 17 MPT measurement coordinate frames A point P in marker coordinates is show along with the corresponding image point Py 19 MPT motion tracking marker with X Y and Z axes of the maker coordinate frame indicated 25902095 tere vases args uates va Ni a cioe ie cus OI NE Oe ae SEE 19 Preview and Graphing Windows with marked MPT markers 23 Illustration of the graphing window showing marker pose plotted in Camera Cartesian Coordinates ne ES NN eut t RR EE 26 Basic processing cycle of program TrackMPT Marker 28 Screen shot showing streaming measurements with example streamed data 33 Graphing output of CameraDaemon TrackMPT Marker 33 An MPT image with marker showing the bar code for Marker ID 26 48 Revised Mar 17 2013 Page iv List of Tables N AUAU Table of alternative display modes Significance of ConfigRunTime xml entries Significance of parameters of the basic run time configuration Significance of ConfigRunTime Significance of ConfigRunTime Significance of ConfigRunTime Significance of ConfigRunTime Cosine Ambiguity Recovery Significance of ConfigRunTi Starburst detection Viro cs ota si ria loe d Be a gc CE a
62. r process benefits from the most recent measurements from all TrackMPT Marker processes 3 1 5 Marker tracking and prediction Moir phase tracking operates by 1 Applying a first order spline to the most recent two locations of the marker to predict the current location followed by 2 Searching for the MPT marker in the neighborhood of the predicted location To support marker tracking When markers are detected and identified by their specific Marker ID Number their location is recorded in the marker context with a call to function RegisterMarkerLocation seen in figure 8 When an image is passed to a TrackMPT Marker process via GrabImage the predicted marker location is also provided Prediction is done with a first order spline fit to the two most recent measured marker locations Testing on a range of spline orders and supports has shown that a first order spline on a two point support gives the highest probability of marker detection at the predicted location perhaps because of the high accelerations sometimes present in human movement Revised Mar 17 2013 Page 12 MPT Users Manual Section 3 1 6 Theory of Operation Shared Memory TrackMPT Marker 1 pO 1 B Du a 1 SR Starburst Tracking N Q g PCA Estimation TR P Ring Buffer amp of Images A Q NN hared E J Memory Q State f Target Context 0 O Starburst Tracking OVA PCA Estimation 89 Q Qo 9 Ring Buffer
63. r saturates at 255 For best accuracy it is important that the MPT landmarks Starburst and circles not saturate in the image The factor that determines the illumination intensity is the exposure duration set when CameraDaemon is launched as described in section 4 1 5 1 1 To adjust the illumination intensity for retro reflective MPT markers In the CameraDaemon preview window type i and or T These keys toggle tools for monitoring the illumination intensity and are described in section 4 1 7 1 Place an MPT marker at the operating distance oriented to approximately directly face the line of sight to the camera but with a small tilt angle to avoid marker front face glare Adjust the exposure time and or the current on the LEDs so that peak intensities in the MPT marker landmarks lie in the range 150 230 without saturating Adjustment guidelines Launch CameraDaemon with various exposure times E option select i and or I in the preview window Fine tune the camera exposure time to produce landmark intensities in the range 150 230 Record the suitable exposure time for later use This will be the standard exposure setting whenever CameraDaemon is launched Revised Mar 17 2013 Page 52 MPT Users Manual Section 6 1 0 Trouble Shooting 6 Trouble shooting 6 1 If the camera does not start If CameraDaemon fails to attach to the camera it will emit the following messages pos
64. rameter S or the parameter nImagesToSave in file ConfigRunTime xml see section 7 2 When the save images action is complete the images will be saved in directory Metria Logging Session Session Date amp Time SavedImages Instance Date amp Time FrameNumber bmp The session date and time mark the time of the first capture by the current session of CameraDaemon The instance date and time mark the date and time of the specific capture of images Multiple collections of images can be saved during a single session t Temperature This hot key toggles camera temperature display on off Note Camera temperature is not supported for all cameras h Flip the preview image horizontally gives the mirror view rather than the tv view may be good for grabbing camera calibration images Revised Mar 17 2013 Page 24 MPT Users Manual Section 4 1 8 Detailed User Manual v Flip the preview image vertically good for collecting camera calibration images via a mirror Preview window will resume displaying images when saving is complete During image saving a second s typed to the preview window will terminate the saving action 4 1 7 3 Preview and Graphing Window Marking Typing an m with the cursor in the preview window toggles activation of Preview and Graphing Window Marking When Preview and Graphing Window Marking is active white cross hairs are drawn in the preview window as seen in fig
65. raphing mode selected from the CameraDaemon command line see section 4 1 8 for the CameraDaemon option to activate graphing An example of the real time plot generated is seen in figure 16 The position data marked XYZPRY is presented as position and orientation in Euler angles The position gt lt Yes p 9 Z T where X YZ is the position of the marker mm in Camera coordinates Revised Mar 17 2013 Page 32 MPT Users Manual Section 4 3 0 Detailed User Manual F F F F F E E F F F F F F F F F F User Bolt 3 J6pURGRURGRProc 000397 000398 000399 000400 000401 000402 000403 000404 000405 000406 000407 000408 000409 000410 000411 000412 000413 267142 Status i XYZPRY 45 5 05 A 259752178 Status XYZPRY z b b B 509 178 Status XYZPRY Eh B 546 178 Status RYZPRY lt 5 185 529 178 Status XYZPRYE 5 B 545 178 Status gt XYZPRY B 528 178 gt Status AXYZPRY B 497 178 Status s AYZPRY P G E 501 178 Status XYZPRY B 5 3 542 178 Status XYZPRY 5 i 503 178 Status XYZPRY 5 5 15 185 549 178 Status XYZPRY 5 15 517 178 Status XYZPRY 5 536 178 gt Status XYZPRY 8 5 5 E 546 178 Status XYZPRY 5 05 bs 522 178 Status XYZPRY B 5 e 517
66. rmal operation Demo Mode will serve up the images mo Mode from a directory at the specified or default frame rate Once the directory is exhausted CameraDaemon exits For continuous operation Demo Mode looping mode can be used to continuously loop through the set of images Notice that the option is the letter 1 ell not the number 1 one user Bolt II bin CameraDaemonFW 1 D tmp Images n To emulate a camera image stream CameraDaemon extracts the right most numeric portion of the image file name and uses it to produce the image frame number To disable this feature and provide sequential frame numbers use the n option user Bolt II bin CameraDaemonFW n D tm p Images w_ To enable processing every image in a directory the waiting mechanism can be invoked using the w option CameraDaemon will wait until TrackMPT each image before loading the next image Marker has processed user Bolt II bin CameraDaemonFW w D tm 4 1 10 Examples of typical CameraDaemon usage p Images General usage for CameraDaemon usually involves setting the Frame rate and exposure also it is nice to use Preview Window and Graphing user Bolt II bin CameraDaemonFW pg F 80 E 600 t may be convenient for CameraDaemon to behave like the camera even though a camera is not present Demo Mode is launch with user Bolt II bin CameraDaemonFW D tmp Images W
67. rom and normal Revised Mar 17 2013 Page 18 MPT Users Manual Section 3 5 0 Theory of Operation to the marker front face The key spoke is the starburst spoke one of the five seen in figure 11 that aligns with a circular landmark In figure 10 note the 180 yaw axis rotation between the camera and marker coordinate frames Camera Frame Image Plane Target Frame Figure 10 MPT measurement coordinate frames A point P in marker coordinates is show along with the corresponding image point P Figure 11 MPT motion tracking marker with X Y and Z axes of the maker coordinate frame indicated Revised Mar 17 2013 Page 19 MPT Users Manual Section 4 1 1 Detailed User Manual 4 Detailed User Manual 4 1 Camera Daemon 4 1 1 Basics of Camera Daemon CameraDaemon is the C language component of the MPT real time system The features intended for normal user operation are listed in this section CameraDaemon related commands are run from a Linux shell normally in either a gnome terminal or xterm window Basic usage is as follows Launch CameraDaemon CameraDaemon should be executed from directory bin user Bolt II MPT TrackingSystem cd bin user Bolt II bin CameraDaemonFW Note the preceding the CameraDaemon command This tells Linux UNIX to take the command from the current working directory If the camera does not start see section 6 1
68. s over full the MPT system will prompt the user to purge the logging partition or exit See section 4 6 3 for more detail 2 2 2 Exiting MPT software following automatic startup To exit MPT processing type C or in the MPT processing terminal window the black window To exit CameraDaemonFW type q in the preview window or type C or in the CameraDaemon terminal window 2 2 3 Manual startup The Bolt II boots to the default processing configuration set in file ConfigRunTime xml However many of the features described in the detailed user manual chapter 4 are accessible by manually starting the two programs CameraDaemonFW TrackMPT Marker Manual startup is described in this section Only one instance of CameraDaemonFW can can run at atime And it is generally best to start CameraDaemonFW first and then TrackMPT Marker So before either program can be manually started any existing instance must be exited as described in section 2 2 2 2 2 3 1 Setting up shielded cores for MPT processing The system will run at optimal performance when the moir phase tracking process or processes execute on a shielded core or cores Shielded cores are CPU cores in the multi core CPU that are dedicated to specified processes Access to the shielded cores is gained with the command LaunchProtectedXterms user localhost cd Metria Software Scripts user Bolt II Scripts LaunchProtectedXterms Revised Mar 17 201
69. se 0 1 0 RG R j RG PM iT ji 20 0 0 1 0 0 0 1 where T j SE 3 R indicates the transformation from camera or c coordinates to marker or f coordinates on the j sample Note that the definition of Euler angles internal to the MPT system is given by Eqn 17 which results in pitch 0 roll 0 yaw 0 when the marker is parallel to the image plane of the camera 7 1 4 For streaming data For streaming data section 4 3 PR and T are defined 10 0 UR ROY RD R 0 1 0 AR 21 0 0 1 PR j P er j j j Q2 7 2 Configuration file ConfigRunTime xml Configuration of the MPT system is set in file ConfigRunTime xml home user mpt ConfigRunTime xml Revised Mar 17 2013 Page 57 MPT Users Manual Section 7 2 0 Appendices ConfigRunTime xml can be edited with any text editor such as gedit vi or emacs The sections of file ConfigRunTime xml are described below Revised Mar 17 2013 Page 58 MPT Users Manual Section 7 2 1 Appendices 7 2 Basic run time configuration Basic run time configuration parameters are listed in table 2 The parameters of greatest interest for the user are UDPHost UDPPort and PhysicalMarkerIDNumber which set the destination of the UDP packets with measurements and the default marker ID number Field Name Example Data Significance Allowed Range or Values Versio
70. sibly among others user Bolt II bin CameraDaemonFW CameraDaemon No Camera found CameraDaemon has been shutdown In this case Check the power and cable connections to the camera Revised Mar 17 2013 Page 53 MPT Users Manual Section 6 2 0 Trouble Shooting 6 2 Steps to take if TrackMPT Marker the MPT process halts with errors on screen In the event that TrackMPT Marker halts with errors please do these things to document the halting condition Take a screen shot which will capture any error messages 2 Record the shared memory state information To take a screen shot simply press the Print Screen key on your keyboard A dialog box will open requesting a file name for the screen shot An appropriate place to save this image would be in Metria Logging Session Session Date amp Time gt Note the session information is displayed during CameraDaemon startup Another piece of useful information is the current state of shared memory This can be saved to a file using the following commands user Bolt II MPT TrackingSystem cd bin user Bolt II bin ShowSharedMemoryState gt Metria Logging Session Session Date amp Time SharedMem txt Revised Mar 17 2013 Page 54 MPT Users Manual Section 7 1 2 Appendices 7 Appendices 7 1 Note on notation In section 4 and elsewhere mathematical notation is used to describe rotation matrices homogeneous transforms and
71. stem s ate cies ow wee xvm werte iuste ue s EU Y E E d 46 MPT marker ID numbers on 5 3 2 2 039 9994 2234 5 Deus Du EA 46 4 8 1 MPT marker ID number and Marker series number 46 2 527 Marker sete S number oe ayo sate oet Supe due eds wk ME d 46 Revised Mar 17 2013 Page ii 7 4 8 3 Marker ID number 2 422253 93 ee as xU galet 4 8 4 Reading the MPT Marker ID number 4 9 Additional utility commands 49 ShowSharedMemoryState 2 22 6 29 eee RR x Dh 4 9 2 Readinfer pt Ime 2c o ok eA bod an d arts ne WC 2 Gees 4 9 3 TagDRTLogFile Log file tagging 4 9 3 1 Creating a tag file 4 uo cR eR Sek eu 4 9 3 2 Breaking out the log files into segments by the tags MPT system adjustments 5 1 Adjusting the illumination intensity 5 1 1 To adjust the illumination intensity for retro reflective MPT markers Trouble shooting 6 1 Ifthe camera does not start i s edo orien Run eomm exo e ues eam 6 2 Steps to take if TracKMPT Marker the MPT process halts with errors on screen Appendices TLL JNoteonhnotatioH 23 xe den eee be ee ee ee ee eee TES TEL POSUIONS gironi ees Bort cee BA end GT cu T T2 Ports azesand POSES ur Soeur Oe Wyo Mle Be Dee De en X FLI Rotations c bas ome s en doe Sue QUAE QUEUE Se ele de ete are TAGE OU SIE AtmIN data cr X ss ns 7 2 Configuration file ConfigRunTime xml
72. t of Starburst focus A measure of the focus of the MPT marker is computed as std Pixels F 10 im max Pixels min Pixels 15 where Pixels is a set of pixels near the center of the StarBurst std Pixels is the standard deviation of intensity min and max are the min and max intensity on the set and Focus is a measure of the sharpness of the focus Eqn 15 operates on the observation that with sharp focus the distribution of intensities near the center of the Starburst approaches a bi modal distribution which maximizes the standard deviation of intensity Softer focus moves pixels toward the middle value Revised Mar 17 2013 Page 39 MPT Users Manual Section 4 4 3 Detailed User Manual reducing the relative magnitude of the standard deviation The focus value is available through the real time display as described in section 4 4 3 4 4 3 Activating real time display modes with UpdateHomogeneousTransforms The coordinate frame functions of Updat eHomogeneousTrans forms are described in section 4 3 3 Here alternative settings are described These are activated with the UpdateHomogeneousTrans forms command and effect how 6 variables are displayed in DisplayMeasurement which continu ously prints measurements to the screen and in the graphic plot Graphing is described in section 4 1 8 Alternate data formats are activated by commands of the form UpdateHomogeneousTransforms Marker ID M
73. t up the MPT processing computer will launch X windows the Linux graphical interface and launch MPT processing in the default processing configuration The default processing configuration is set in file ConfigRunTime xml described in chapter 4 and appendix 7 2 The desktop configuration at startup is seen in figure 6 Figure 6 Screen shot of the Bolt II computer upon booting Program TrackMPT Marker is automatically launched The program CameraDaemonFW runs in the upper left described in chapter 3 and section 4 1 The image preview window is seen above the CameraDaemon window Two black terminal windows are seen in the in lower left Each is a Linux shell bash running on a shielded core described in section 2 2 3 1 These windows are referred to as the shielded core windows Revised Mar 17 2013 Page 5 MPT Users Manual Section 2 2 3 Quick Start Guide The program TrackMPT Marker is launched in the upper shielded core window described in chapter 3 and section 4 2 Following boot up the moir phase tracking system is running in the default configuration and emitting UDP packets When a recognized MPT marker is visible in the image measurements will stream on the screen in the graphing window if activated in the UDP packets Caution The MPT system logs measurement data as well as exceptions and images under certain circumstances see sections 3 1 3 1 and 4 6 If the logging partition i
74. the pose of a virtual marker in room coordinates This pose is given according to T DE Tor 11 where T j SE 3 is the current measurement of virtual marker pose in room coordinates this is the pose displayed in both the text and graphical streaming outputs T SE 3 is the transformation from camera to room coordinates T j SE 3 is current measurement of the marker pose described in section 7 1 T SE 3 is the transformation from the virtual marker pose to the physical marker pose and where SE 3 C R is the special Euclidean group it is the set of homogeneous transforms Homogeneous transform T is written mus unnm mao ed 12 0 0 0 1 where R j SO 3 C R specifies the rotation matrix from virtual marker to room coordinates at time t j and P j is the position of the virtual marker in room coordinates Note modifying transforms 7T or T modifies only the streaming output for viewing The pose data emitted in the UDP packet and logging files is always the pose of the physical marker in camera coordinates Revised Mar 17 2013 Page 34 MPT Users Manual Section 4 3 2 Detailed User Manual 4 3 2 Setting T and T with UpdateHomogeneousTransforms The measurement coordinate frame and marker coordinate frame can be set by modifying 7 T and T in Eqn 11 By setting 77 the measurement coordinate frame room coordinates is established By setting T
75. ure 12 Black s are drawn at the edges of the graphing window also seen in figure 12 Lixpot 4 xj 0 9 Physical Target ID Number 10 X mm EN mnl d as 04 14 3009 Z mm ou LL pii anana na ha hait iil A Manaa t Lu E n 93 dr M M n ne ar mere mis roll deg Figure 12 Preview and Graphing Windows with marked MPT markers Action of m key stroke If m is typed and Preview and Graphing Window Marking is off If one or more MPT markes are currently being tracked Activate marking mark current location of MPT marker s in the preview image If there is no MPT marker currently being tracked no action If m is typed and Preview and Graphing Window Marking is on deactivate marking To update marker location s type m twice toggle off then on As seen in figure 12 when tracking multiple markers Preview and Graphing Window Marking will mark all markers in the preview window Revised Mar 17 2013 Page 25 MPT Users Manual Section 4 1 9 Detailed User Manual 4 1 8 Graphing a continuous plot of the MPT marker pose The graphing option will display a graph of X Y Z Pitch Roll and Yaw The plot is automatically scaled according to the collected data Graphing is launched with the bShowGraphingWindow parameter in ConfigRunTime xml or with
76. vide the TrackMPT Marker function with every N image coming from the camera The default under sample rate is 1 If you would like to process images at 30 fps but maintain a flash frequency of 60 Hertz you could run CameraDaemon with the following options user Bolt II bin CameraDaemonFW F 60 U 2 In this case every 2 7 image is provided to TrackMPT Marker and the other half of the images are discarded Image save count and image save rate An s typed to the preview window launches image save see section 4 1 7 1 The number of images to save can be set in ConfigRunTime xml or set when running CameraDaemon using the S flag Setting this parameter on the CameraDaemon command line will override the default configured in ConfigRunTime xml see 7 2 Revised Mar 17 2013 Page 22 MPT Users Manual Section 4 1 7 Detailed User Manual 4 1 6 4 1 7 The rate at which images are saved can be set when running CameraDaemon using the R flag Setting this parameter on the CameraDaemon command line will override the default configured in ConfigRunTime xml see 7 2 This is the image save rate in images per second Note The system will provide a rate closest to the requested rate based on an integer divisor of camera frame rate For example if the camera is running at 60 fps and the user requests a image save rate of 25 ips the system will provide a image save rate of 30 ips Exposure The exposure for

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